Paramedics are the newest troops in the fight against San Diego’s ever-growing hepatitis A outbreak.

A letter signed this week by the director of the state Emergency Medical Services Authority temporarily expands state laws that govern paramedics, granting them emergency powers to “vaccinate at-risk populations in response to the outbreak.”

Dr. Kristi Koenig, director of the San Diego County Emergency Medical Service, requested the temporary scope of practice expansion on Sept. 20 and said Wednesday night that she received approval in the mail Tuesday.

Paramedics will be able to deliver hepatitis A doses only under the supervision of nurses and only at special events created to inoculate those who are at high risk of infection, including homeless residents, drug users and those with liver disease or compromised immune systems.

Usually only nurses and doctors are allowed to give the vaccine.

“Paramedics already have basic skills in terms of delivering injections, and this approval allows us to give them extra training to do vaccination but only in very specific settings with very specific oversight,” Koenig said, adding that they will not be able to administer vaccines during emergency calls.

She said getting the state to approve the request took a fair bit of back-and-forth with California regulators. Assemblyman Todd Gloria, D-San Diego, added a letter of his own urging approval on Sept. 27.

Gloria said Wednesday evening that he believes paramedics can take pressure off public health nurses who have been engaged in a large and growing public vaccination campaign to stop the outbreak, which has now killed 17 people and sickened nearly 500 people throughout the region.